Autoimmune uveitis mediated by T cells is a major cause of blindness in the USA and worldwide, particularly among relative young and working populations. Proposed studies will focus on the danger signals in pathogenesis of chronic autoimmune uveitis using a murine model induced by the adoptive transfer of interphotoreceptor retinoid-binding protein (IRBP)-specific T cells. Aims described in this proposal will examine the release of danger signals initiated by uveitogenic IRBP-specific T cells, and the role of them in ocular inflammation. Aim 1 will determine the Fas/FasL signaling in rapid release of HMGB1 from viable retinal cells after interaction with IRBP-specific T cells. Aim 2 will examine the roleof HMGB1 in sustaining and promoting IRBP-specific T cell function during chronic intraocular inflammation. Results of these studies will further our understanding of the molecular pathogenesis of autoimmune uveitis and identify novel targets for anti-inflammatory intervention to limit visual loss.